IRON(II)-MEDIATED REARRANGEMENT OF 1,2,4-TRIOXANES INTO 1,2-DIOL MONOESTERS VIA 1,5-HYDROGEN TRANSFER

摘要

Five 3-alkyl- or 3-aryl-5,5,6,6-tetramethyl-1,2,4-trioxanes 4 upon treatment with iron(II) sulfate in aqueous acetonitrile under nitrogen for 12-72h are cleanly isomerised into the corresponding 2,3-dimethylbutan-2,3-diol monoesters 5; it is suggested that the reactions involve reduction to oxyl radicals followed by 1,5-hydrogen transfer, a sequence that has recently been implicated in the molecular mechanism of action of the antimalarial artemisinin. [References: 10]